Hydrogen Permeation
Mostrando 1-12 de 14 artigos, teses e dissertações.
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1. Influence of Nanoxides on Diffusivity and Solubility of Hydrogen in Pd-based alloys
The hydrogen interaction in palladium alloys with addition of Ce, Zr and Y was studied. These alloys are produced by arc-melting and then cold rolled into thin foils. Heat treatment at 800ºC for 24h in air atmosphere is applied to induce internal oxidation. Hydrogen permeation tests and TDS (Thermal Desorption Spectroscopy) are carried out to evaluate hydro
Mat. Res.. Publicado em: 11/01/2018
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2. CHARACTERISATION OF ASYMMETRIC ALUMINA HOLLOW FIBRES: APPLICATION FOR HYDROGEN PERMEATION IN COMPOSITE MEMBRANES
Abstract Asymmetric alumina hollow fibres produced by the phase inversion/sintering method present advantages in that high area/volume ratios and low mass transfer resistances are achieved due to the geometric configuration and the pore size distribution, respectively. Here we characterise hollow fibres that were prepared with different internal coagulants a
Braz. J. Chem. Eng.. Publicado em: 2016-09
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3. Synthesis and applications of polystyrene-block-poly(N-vinyl-2-pyrrolidone) copolymers
Abstract This work describes the synthesis and applications of amphiphilic polystyrene-block-poly(N-vinyl-2-pyrrolidone) (PS-b-PVP) copolymers as a silver and silica nanoparticle surface modification agent. The synthesis of PS-b-PVP was carried out using controlled/living radical polymerization techniques. The synthesis of the block copolymers was confirmed
Polímeros. Publicado em: 15/03/2016
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4. EVALUATING HYDROGEN PRODUCTION IN BIOGAS REFORMING IN A MEMBRANE REACTOR
Abstract Syngas and hydrogen production by methane reforming of a biogas (CH4/CO2 = 2.85) using carbon dioxide was evaluated in a fixed bed reactor with a Pd-Ag membrane in the presence of a nickel catalyst (Ni 3.31% weight)/γ-Al2O3) at 773 K, 823 K, and 873 K and 1.01×105 Pa. Operation with hydrogen permeation at 873 K increased the methane conversion to
Braz. J. Chem. Eng.. Publicado em: 2015-03
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5. Hydrogen gas permeation through amorphous and partially crystallized Fe40Ni38Mo4B18
Samples of amorphous and partially crystallized Fe40Ni38Mo4B18 alloy were submitted to hydrogen gas permeation from 523 to 643 K. The hydrogen permeation curves exhibited a single sigmoidal shape, typical of tests where no hydride formation occurs. It was observed that the hydrogen diffusivity increases for the amorphous samples and partially crystallized al
Mat. Res.. Publicado em: 30/08/2012
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6. Estudo da permeação de hidrogênio em reator com membrana de paládio: modelagem matemática e simulação computacional
Hydrogen is the simplest and most common element in the universe. Currently, some industries use hydrogen to refine oil, and to produce ammonia and methanol. Since the combustion of hydrogen produces only water and energy, it is considered to be viable and environmentally safe. Most of the hydrogen produced in industrial scale is by the steam reforming proce
Publicado em: 2009
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7. Efeitos de terpenos nas membranas de estrato córneo estudados por ressonância paramagnética eletrônica / Effects of terpenes on the stratum corneum membranes studied by electron paramagnetic resonance
The interaction of the skin penetration enhancers DL-menthol, -terpineol, 1,8-cineole and (+)-limonene with membranes of the uppermost skin layer, the stratum corneum (SC) and with multilamellar vesicles from 1,2-dipalmitoyl-sn-glycero-3-phosphaticylcholine (DPPC)is investigated by electron paramagnetic resonance (EPR) spectroscopy using spin-labeled
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 18/02/2008
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8. Poli(oxido de etileno-co-epicloridrina) : degradação foto-oxidativa e termica, e blenda com polipropileno
Polymers derived from ethylene oxide and epichlorohydrin, like poly(epichlorohydrin-co-ethylene oxide) elastomer, are studied as polymer electrolyte for application in photo-electrochemical devices. These materiaIs present the ability to form complexes with alkali salts, presenting high ionic conductivity. In these devices the conversion of the solar energy
Publicado em: 2003
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9. Dynamic mechanisms of the membrane water channel aquaporin-1 (AQP1)
Molecular-dynamics simulations were performed on the structures of the water channel aquaporin-1. The results provide an atomistic description of the interactions involved in the water permeation. Two major curvilinear pathways were identified. The simulations confirmed that the water selectivity is due primarily to the size-exclusion effect; i.e., maxi
The National Academy of Sciences.
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10. Structure and dynamics of a proton wire: a theoretical study of H+ translocation along the single-file water chain in the gramicidin A channel.
The rapid translocation of H+ along a chain of hydrogen-bonded water molecules, or proton wire, is thought to be an important mechanism for proton permeation through transmembrane channels. Computer simulations are used to study the properties of the proton wire formed by the single-file waters in the gramicidin A channel. The model includes the polypeptidic
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11. Solvation, water permeation, and ionic selectivity of a putative model for the pore region of the voltage-gated sodium channel.
This paper describes a molecular dynamics and molecular mechanics study of the solvation and selectivity of the narrow pore and vestibule region of a model-built structure for the voltage-gated sodium channel. The particular structure used was one proposed by Guy and Durell. However, many of the features we saw would likely be shared with other possible mode
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12. Rapid polyether cleavage via extracellular one-electron oxidation by a brown-rot basidiomycete
Fungi that cause brown rot of wood are essential biomass recyclers and also the principal agents of decay in wooden structures, but the extracellular mechanisms by which they degrade lignocellulose remain unknown. To test the hypothesis that brown-rot fungi use extracellular free radical oxidants as biodegradative tools, Gloeophyllum trabeum was examined for
The National Academy of Sciences.